The Arduino Mega's PWM pins are digital output pins located on D2 to D13 and D44 to D46, coming to a total of 15.

Each individual pin takes 12-13 cycles to address, totally 9984 cycles at worst when addressing the maximum number of outputs. [Elco] thinks this is as fast as he can make the routine run, but he ...

Options to power the Arduino Nano include USB, VIN, and 5 volt pin, meaning you have power options for almost any situation.